WASHINGTON  Supreme Court justices struggled Wednesday with whether government must accept all donated monuments once it opens a park to any markers, raising several dramatic, even fanciful, scenarios.

"You have a Statue of Liberty," Chief Justice John Roberts said. "So we have to have a statue of despotism? Or do we have to put any president who wants to be on Mount Rushmore?"

During a spirited hour, the justices suggested they were not ready to affirm a lower-court decision that said the First Amendment's free-speech guarantee requires a government to accept all monuments from private parties once it has accepted others.

The opinion by the U.S. Court of Appeals for the 10th Circuit would require Pleasant Grove, Utah, to accept the Summum church's "Seven Aphorisms" monument because the city accepted a Ten Commandments monument in a park 40 years ago.

Yet, it was not clear what sorts of legal lines the court majority might draw to govern situations across the country. Several justices noted that the case could return to them as a test of when a city's acceptance of a particular religious monument violates the Constitution's separation of church and state.

Summum, founded in 1975, adopts Egyptian customs, such as mummification, with elements of Gnostic Christianity that teach spiritual knowledge is experiential.

The Summum church sued Pleasant Grove after the city in 2003 rejected its request erect a monument in Pioneer Park to its seven aphorisms, principles including "vibration," "rhythm" and "opposition." City officials said they wanted only monuments that related to Pleasant Grove history or were donated by groups with long-standing ties to the town.

Lawyer Jay Sekulow, representing Pleasant Grove, told justices that when the city accepted the Ten Commandments monument from the Fraternal Order of Eagles in 1971, the marker became "government speech." He argued the city did not create a true "public forum" and can turn down other bids by private groups with monuments.

Deputy U.S. Solicitor General Daryl Joseffer, siding with Pleasant Grove, said the federal government has wide latitude on what goes on the National Mall and in parks. "The Vietnam Veterans Memorial did not open us up to a Viet Cong memorial," he said.

Lawyer Pamela Harris, for Summum, told the justices, "The city here gave the Eagles access to its public park for a display about the Ten Commandments and it denied Summum access … That's a violation of the core free-speech principle that the government may not favor one message over another."

She argued the Eagles' Ten Commandments marker must be seen as private, not government, speech because the city did not control the monument's content. She said once a city sets up a forum for private messages, it must generally take all.

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